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Institute of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! Member of the Leibniz Association
Motion Compensation inPositron Emission Tomography:
Performance of a Clinical Integration at the PET centre Dresden-Rossendorf
Jens LangnerPET centre - Institute of Radiopharmacy
Research Centre Dresden-Rossendorf, Germany
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Agenda
• introduction of the FZD and its PET facility
• motivation for working on motion compensation
• motion tracking and quantification of patient motion
• why list-mode? solved problems with ECAT scanners
• event-based motion compensation, its challanges and performance
• methods for clinical integration
• conclusion / summary
2
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Introduction - the FZD
• Established: 1992
• Employees: ! 750,! 330 scientists (! 120 Ph.D. candidates)
• Budget: ! 61 Mio "
• Member of Leibniz Association
• 6 institutes and 6 large-scale facilities
Dresden
Ion Beam Centre
Radiation Source ELBE
Rossendorf Beamline
PET Centre
TOPFLOW Facility
Dresden High Magnetic Field Laboratory
Ion Beam Physics andMaterials Research
Radiation Physics
Radiochemistry
Radiopharmacy
Safety Research
High Magnetic Field Laboratory
Advanced Materials Research
Nuclear Safety Research
Cancer Research
3
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Introduction - the FZD
• Established: 1992
• Employees: ! 750,! 330 scientists (! 120 Ph.D. candidates)
• Budget: ! 61 Mio "
• Member of Leibniz Association
• 6 institutes and 6 large-scale facilities
Dresden
Ion Beam Centre
Radiation Source ELBE
Rossendorf Beamline
PET Centre
TOPFLOW Facility
Dresden High Magnetic Field Laboratory
Ion Beam Physics andMaterials Research
Radiation Physics
Radiochemistry
Radiopharmacy
Safety Research
High Magnetic Field Laboratory
Advanced Materials Research
Nuclear Safety Research
Cancer Research
PETcentre
3
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Introduction - PET centre
interdisciplinary group:
radiochemistrybiochemistrybiologymedicinecomputer sciencephysics
facilities:
cyclotronradiochemical laboratories (GMP)human + small animal PETsmall animal MRI and CThuman PET/MRI (in Q2/2010)
PET tracers:
16F-FDG, 18F-OMFD,18F-FDOPA, NaF, 11C-Acetate, 15O-water (GMP), ...
• Established: 1995
• In cooperation with the nuclear medicine department of the Technical University Dresden
• Head:Prof. Dr. Dr. Jörg van den Hoff
4
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Introduction - PET centre
Research focus - PET group• radiotracer development
• preclinical and clinical PET studies in oncology and neurology
• characterization of selected parameters for PET-guided therapy response monitoring
• PET in radiation treatment planning
• quantitative evaluation of tracer kinetics
• multi-modality in vivo imaging
• PET in pharmaceutical research
5
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Introduction - PET centre
Research focus - PET group• radiotracer development
• preclinical and clinical PET studies in oncology and neurology
• characterization of selected parameters for PET-guided therapy response monitoring
• PET in radiation treatment planning
• quantitative evaluation of tracer kinetics
• multi-modality in vivo imaging
• PET in pharmaceutical research
• improvement of PET imaging:
- optimized ROI delineation:e.g. automatic background dependent 3D-ROI delineation and segmentation
- utilization of list-mode data
- motion compensation techniques
5
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - Motion Compensation
• PET is a functional method for imaging of biochemical and physiological processes in vivo
• provides absolute quantitative values for evaluation of metabolic processes
• current spatial resolution: ! 5 mm (brain), ! 8 mm (whole body)
• recent developments (e.g. PSF optimized reconstructions) demonstrate the feasibility of ! 2 mm
• acquisition times of several minutes to hours are unavoidable(low signal/noise ratio, dynamic acquisitions, etc.)
6
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - Motion Compensation
• PET is a functional method for imaging of biochemical and physiological processes in vivo
• provides absolute quantitative values for evaluation of metabolic processes
• current spatial resolution: ! 5 mm (brain), ! 8 mm (whole body)
• recent developments (e.g. PSF optimized reconstructions) demonstrate the feasibility of ! 2 mm
• acquisition times of several minutes to hours are unavoidable(low signal/noise ratio, dynamic acquisitions, etc.)
!patient movement increasingly limits the achievable spatial resolution in PET ...
6
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - Motion Compensation
... and immobilizations are of limited help only
7
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - Consequences of patient motion
1. Intra-frame movement (dynamic + static acquisitions):
– loss in resolution („motion blurring“)
– reconstruction/image artifacts
– systematic errors in quantitative evaluations(e.g. standardized uptake value - SUV - in FDG whole body)
2. Inter-frame movement (dynamic acquisitions):
– incorrect registration between frames
– (massive) systematic errors in time-activity-curves (TAC)
– systematic errors in quantification of tracer kinetics
8
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - Qualitative Consequences
Example: 18F-FDG PET
without motion with patient motion
0.0
[Bq/c
c]10280.0
9
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - Quantitative Consequences
time-activity-curve (TAC)
Sagittal
Transaxial
Bq/c
c0.0
10290.0
0 5 10 15 20 25 30 35 40 45 50
10.000
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Zeit [min]
Konzentr
ati
on [
Bq/cc]
expected progression (without motion)
male, 75 years18F-DOPA (M. Parkinson)248 MBq i.v.55 min dynamic emission(27 frames)
conce
ntr
atio
n [
Bq/c
c]
time [min]
10
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - many approaches...1: Fin L, Bailly P, Daouk J, Meyer ME. Motion correction based on an appropriate system matrix for statistical reconstruction of respiratory-correlated PET acquisitions. Comput Methods Programs Biomed. 2009 May 30. [Epub ahead of print] PubMed PMID: 19487044.2: Costes N, Dagher A, Larcher K, Evans AC, Collins DL, Reilhac A. Motion correction of multi-frame PET data in neuroreceptor mapping: Simulation based validation. Neuroimage. 2009 May 27. [Epub ahead of print] PubMed PMID: 19481154.3: Wang X, Koch S. Positron emission tomography/computed tomography potential pitfalls and artifacts. Curr Probl Diagn Radiol. 2009 Jul-Aug;38(4):156-69. PubMed PMID: 19464586.4: Büther F, Dawood M, Stegger L, Wübbeling F, Schäfers M, Schober O, Schäfers KP. List mode-driven cardiac and respiratory gating in PET. J Nucl Med. 2009 May;50(5):674-81. Epub 2009 Apr 16. PubMed PMID: 19372491.5: Bai W, Brady M. Regularized B-spline deformable registration for respiratory motion correction in PET images. Phys Med Biol. 2009 May 7;54(9):2719-36. Epub 2009 Apr 8. PubMed PMID: 19351979.6: Nagamachi S, Wakamatsu H, Kiyohara S, Fujita S, Futami S, Arita H, Nishii R, Tamura S, Kawai K. Usefulness of a deep-inspiration breath-hold 18F-FDG PET/CT technique in diagnosing liver, bile duct, and pancreas tumors. Nucl Med Commun. 2009 May;30(5):326-32. PubMed PMID: 19282791.7: Yamaguchi T, Ueda O, Hara H, Sakai H, Kida T, Suzuki K, Adachi S, Ishii K. Usefulness of a breath-holding acquisition method in PET/CT for pulmonary lesions. Ann Nucl Med. 2009 Jan;23(1):65-71. Epub 2009 Feb 11. PubMed PMID: 19205840.8: Faber TL, Raghunath N, Tudorascu D, Votaw JR. Motion correction of PET brain images through deconvolution: I. Theoretical development and analysis in software simulations. Phys Med Biol. 2009 Feb 7;54(3):797-811. Epub 2009 Jan 9. PubMed PMID: 19131672.9: Raghunath N, Faber TL, Suryanarayanan S, Votaw JR. Motion correction of PET brain images through deconvolution: II. Practical implementation and algorithm optimization. Phys Med Biol. 2009 Feb 7;54(3):813-29. Epub 2009 Jan 9. PubMed PMID: 19131667.10: Hofmann M, Pichler B, Schälkopf B, Beyer T. Towards quantitative PET/MRI: a review of MR-based attenuation correction techniques. Eur J Nucl Med Mol Imaging. 2009 Mar;36 Suppl 1:S93-104. Review. PubMed PMID: 19104810.11: Daouk J, Fin L, Bailly P, Meyer ME. Respiratory-gated positron emission tomography and breath-hold computed tomography coupling to reduce the influence of respiratory motion: methodology and feasibility. Acta Radiol. 2009 Mar;50(2):144-55. PubMed PMID: 19096952.12: Cheng NM, Yu CT, Ho KC, Wu YC, Liu YC, Wang CW, Yen TC. Respiration-averaged CT for attenuation correction in non-small-cell lung cancer. Eur J Nucl Med Mol Imaging. 2009 Apr;36(4):607-15. Epub 2008 Dec 3. PubMed PMID: 19050875.13: Slomka PJ, Le Meunier L, Hayes SW, Acampa W, Oba M, Haemer GG, Berman DS, Germano G. Comparison of myocardial perfusion 82Rb PET performed with CT- and transmission CT-based attenuation correction. J Nucl Med. 2008 Dec;49(12):1992-8. PubMed PMID: 19038996.14: Lucignani G. Respiratory and cardiac motion correction with 4D PET imaging: shooting at moving targets. Eur J Nucl Med Mol Imaging. 2009 Feb;36(2):315-9. Review. PubMed PMID: 19030856.15: Bundschuh RA, Martinez-Müller A, Essler M, Nekolla SG, Ziegler SI, Schwaiger M. Local motion correction for lung tumours in PET/CT--first results. Eur J Nucl Med Mol Imaging. 2008 Nov;35(11):1981-8. Epub 2008 Aug 6. PubMed PMID: 18682940.16: Daouk J, Fin L, Bailly P, Meyer ME. Improved attenuation correction via appropriate selection of respiratory-correlated PET data. Comput Methods Programs Biomed. 2008 Oct;92(1):90-8. Epub 2008 Aug 3. PubMed PMID: 18676054.17: Fin L, Daouk J, Morvan J, Bailly P, El Esper I, Saidi L, Meyer ME. Initial clinical results for breath-hold CT-based processing of respiratory-gated PET acquisitions. Eur J Nucl Med Mol Imaging. 2008 Nov;35(11):1971-80. Epub 2008 Jun 26. PubMed PMID: 18581114.18: Janssen MH, Aerts HJ, Ollers MC, Bosmans G, Lee JA, Buijsen J, De Ruysscher D, Lambin P, Lammering G, Dekker AL. Tumor delineation based on time-activity curve differences assessed with dynamic fluorodeoxyglucose positron emission tomography-computed tomography in rectal cancer patients. Int J Radiat Oncol Biol Phys. 2009 Feb 1;73(2):456-65. Epub 2008 Jun 14. PubMed PMID: 18556143.19: Schäfers KP, Stegger L. Combined imaging of molecular function and morphology with PET/CT and SPECT/CT: image fusion and motion correction. Basic Res Cardiol. 2008 Mar;103(2):191-9. Review. PubMed PMID: 18324375.20: Alessio A, Kohlmyer S, Kinahan P. Consistency Driven Respiratory Phase Alignment and Motion Compensation in PET/CT. IEEE Nucl Sci Symp Conf Rec (1997). 2007;4:3115-3119. PubMed PMID: 19266056.
11
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - ... but only a handful of paths
system matrixmodifications
withinreconstruction
multiple acquisition framing (MAF)
event-by-event correctionbeforereconstruction
listmode-based
CMS movementsinogram-based
co-registrationinter-frame
n/aintra-frameimage-based
Compensationtechniques
incorrect volumedelineation
TAC / SUV
quantitative effects
image artifacts
resolution loss (blurring)
Consequences
Patient motionin PET
12
! motion compensation for brain acquisitions in PET
• using the „raw data“ (list-mode) of a PET scanner
• using an external motion tracking device
• focused on clinical usability
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motivation - our approach
1) motion tracking and quantification of motion
2) routine acquisition of list-mode data
3) development and optimization of an event-based motion compensation algorithm
4) methods for integration into clinical routine(e.g. graphical user interfaces)
Tasks
13
• External motion tracking device(infrared video cameras - ARTtrack)
– spatial resolution better than 1 mm
– time resolution < 50 ms
– output of all six degrees of freedom (3x translations, 3x rotations)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Tracking
Methods:
1.Installation/Calibration:e.g. calibration with PET coordinate system
2.Development and evaluation of a suitable motion target
3.Integration into clinical routine
14
http://www.ar-tracking.de/
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Tracking - Target development
• Problem: motion target has to output the true patient motion.
15
compare
teeth moulded target(as a reference)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Tracking - Target development
• Problem: motion target has to output the true patient motion.
15
compare
teeth moulded target(as a reference)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Tracking - Target evaluation results
16
I II III IV V
0.0 0.2 0.4 0.6 0.8 1.0
269.9
270.0
270.1
270.2
270.3
270.4
270.5
Euclidian difference
time [min]
tota
l [m
m]
min: 269.903 max: 270.489 diff: 0.586 mm
0.0 0.2 0.4 0.6 0.8 1.0
278
279
280
281
282
283
284
target 0 displacement vector length
time [min]
tota
l [m
m]
min: 279.515 max: 282.261 diff: 2.746 mm
0.0 0.2 0.4 0.6 0.8 1.0
327
328
329
330
331
332
333
target 1 displacement vector length
time [min]
tota
l [m
m]
min: 327.120 max: 333.130 diff: 6.010 mm
Comparison between target 0 and target 1 (Tracking Coordinates)
Page 2/4test28.trk
Thu Aug 30 17:32:52 2007analyze_trk.R $Revision: 194 $ ! (c) 2005!2007 fzd.de
time [min]
dist
ance
[mm
]
�d = 0.6 mm
0.0 0.2 0.4 0.6 0.8 1.0
330.0
330.5
331.0
331.5
332.0
Euclidian difference
time [min]
tota
l [m
m]
min: 329.698 max: 331.960 diff: 2.262 mm
0.0 0.2 0.4 0.6 0.8 1.0
356
358
360
362
364
366
368
target 0 displacement vector length
time [min]
tota
l [m
m]
min: 354.977 max: 369.313 diff: 14.336 mm
0.0 0.2 0.4 0.6 0.8 1.0
242
244
246
248
250
252
254
256
target 1 displacement vector length
time [min]
tota
l [m
m]
min: 241.194 max: 255.374 diff: 14.180 mm
Comparison between target 0 and target 1 (Tracking Coordinates)
Page 2/4test21.trk
Thu Aug 30 17:25:10 2007analyze_trk.R $Revision: 194 $ ! (c) 2005!2007 fzd.de
dist
ance
[mm
]
time [min]
�d = 2.3 mm
0.0 0.2 0.4 0.6 0.8 1.0
302
303
304
305
306
Euclidian difference
time [min]
tota
l [m
m]
min: 302.090 max: 306.303 diff: 4.213 mm
0.0 0.2 0.4 0.6 0.8 1.0
224
226
228
230
232
234
236
target 0 displacement vector length
time [min]
tota
l [m
m]
min: 224.923 max: 234.322 diff: 9.398 mm
0.0 0.2 0.4 0.6 0.8 1.0
362
364
366
368
370
372
374
376
target 1 displacement vector length
time [min]
tota
l [m
m]
min: 362.472 max: 375.965 diff: 13.493 mm
Comparison between target 0 and target 1 (Tracking Coordinates)
Page 2/4test18.trk
Thu Aug 30 17:21:46 2007analyze_trk.R $Revision: 194 $ ! (c) 2005!2007 fzd.de
dist
ance
[mm
]
time [min]
�d = 4.2 mm
(a)
(b)
(c)
Euclidean distance plot
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Tracking - Target evaluation results
16
I II III IV V
0.0 0.2 0.4 0.6 0.8 1.0
269.9
270.0
270.1
270.2
270.3
270.4
270.5
Euclidian difference
time [min]
tota
l [m
m]
min: 269.903 max: 270.489 diff: 0.586 mm
0.0 0.2 0.4 0.6 0.8 1.0
278
279
280
281
282
283
284
target 0 displacement vector length
time [min]
tota
l [m
m]
min: 279.515 max: 282.261 diff: 2.746 mm
0.0 0.2 0.4 0.6 0.8 1.0
327
328
329
330
331
332
333
target 1 displacement vector length
time [min]
tota
l [m
m]
min: 327.120 max: 333.130 diff: 6.010 mm
Comparison between target 0 and target 1 (Tracking Coordinates)
Page 2/4test28.trk
Thu Aug 30 17:32:52 2007analyze_trk.R $Revision: 194 $ ! (c) 2005!2007 fzd.de
time [min]
dist
ance
[mm
]
�d = 0.6 mm
0.0 0.2 0.4 0.6 0.8 1.0
330.0
330.5
331.0
331.5
332.0
Euclidian difference
time [min]
tota
l [m
m]
min: 329.698 max: 331.960 diff: 2.262 mm
0.0 0.2 0.4 0.6 0.8 1.0
356
358
360
362
364
366
368
target 0 displacement vector length
time [min]
tota
l [m
m]
min: 354.977 max: 369.313 diff: 14.336 mm
0.0 0.2 0.4 0.6 0.8 1.0
242
244
246
248
250
252
254
256
target 1 displacement vector length
time [min]
tota
l [m
m]
min: 241.194 max: 255.374 diff: 14.180 mm
Comparison between target 0 and target 1 (Tracking Coordinates)
Page 2/4test21.trk
Thu Aug 30 17:25:10 2007analyze_trk.R $Revision: 194 $ ! (c) 2005!2007 fzd.de
dist
ance
[mm
]
time [min]
�d = 2.3 mm
0.0 0.2 0.4 0.6 0.8 1.0
302
303
304
305
306
Euclidian difference
time [min]
tota
l [m
m]
min: 302.090 max: 306.303 diff: 4.213 mm
0.0 0.2 0.4 0.6 0.8 1.0
224
226
228
230
232
234
236
target 0 displacement vector length
time [min]
tota
l [m
m]
min: 224.923 max: 234.322 diff: 9.398 mm
0.0 0.2 0.4 0.6 0.8 1.0
362
364
366
368
370
372
374
376
target 1 displacement vector length
time [min]
tota
l [m
m]
min: 362.472 max: 375.965 diff: 13.493 mm
Comparison between target 0 and target 1 (Tracking Coordinates)
Page 2/4test18.trk
Thu Aug 30 17:21:46 2007analyze_trk.R $Revision: 194 $ ! (c) 2005!2007 fzd.de
dist
ance
[mm
]
time [min]
�d = 4.2 mm
(a)
(b)
(c)
Euclidean distance plot
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Quantification - ambiguity problem
• Problem: drawing conclusions on the significance of motion from the six degrees of freedom can be ambiguous
17
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Quantification - ambiguity problem
• Problem: drawing conclusions on the significance of motion from the six degrees of freedom can be ambiguous
17
" " "
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Quantification - ambiguity problem
• Problem: drawing conclusions on the significance of motion from the six degrees of freedom can be ambiguous
17
? ? ?
" " "
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Quantification - Method
Method:
1.apply the motion parameters to selected points on an imaginary spherewithin the FOV (sphere approximates a human head ! 20 cm diameter)
2.calculate the euclidean distance for each point
18
(a)
x
y
z
(b)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Quantification - Example
19
!10 0 10 20 30 40 50
05
10
15
20
acquisition time [min]
mo
ve
me
nt
[mm
]
10 sign.motion found on artifical head surface (r=100mm)3 sign.motion found in mean striatum areas
"best" point on head surface
"worst" point on head surface
L striatum [p1=56:60:36]
R striatum [p2=78:60:36]
point of motion > 4 mm
frame boundaries
accessible range on head surface
"best" point on head surface (10%!90%) = 0.8!7.5 mm
minimum movement [mm]
Fre
qu
en
cy
0 2 4 6 8
02
00
04
00
0
"worst" point on head surface (10%!90%) = 0.8!17.7 mm
maximum movement [mm]
Fre
qu
en
cy
0 5 10 15 20
02
00
04
00
06
00
0
sphere angle !! [deg]
sp
he
re a
ng
le ""
[d
eg
]
0 45 90 135 180 225 270 315 360
04
59
01
35
18
0
Neck
Os temporale (L)
Os parietale
Neck
Os nasale
Os parietale
Neck
Os temporale (R)
Os parietale
Neck
Os occipitale
Os parietale
distance fluctuation map (sd.) ! max. = +/!7.3 mm
01
23
45
67
sphere angle !! [deg]
sp
he
re a
ng
le ""
[d
eg
]
0 45 90 135 180 225 270 315 360
04
59
01
35
18
0
Neck
Os temporale (L)
Os parietale
Neck
Os nasale
Os parietale
Neck
Os temporale (R)
Os parietale
Neck
Os occipitale
Os parietale
mean distance to source point map ! max. = 10.1 mm
02
46
81
0
Patient head movement analysis with significant motion (> 4 mm) selected:
Page 2/3./hackbarth_070911.tfm
Tue Sep 11 13:58:11 2007analyze_trk.R $Revision: 195 $ ! (c) 2005!2007 fzd.de
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Motion Quantification - Example
20
40
50
60
Neck
70
80
0350
340
10
3020
40 50 60 80709090
100
150
140
130
110120
160
170
180
190
200
300
310
320
330
100
Os temporale (L)
110
120
Os nasale
130
Min point
Max point
140
150
160
170180
Os parietale
Os temporale (R)Os occipitale
290
280
270
260250
240 220230
210
0
10
20
30
Neck
50
60
70
80
10
20
30
0
350
40
5060
100
110
120
130
150
140
160
170
190
180
200210
220230 240 250 260 270
280290
300
310
320
340
330Os temporale (R)
Os occipitale
Os parietale
180
170
160
150
Os temporale (L)
140
Max point
Min point
130
120
Os nasale
110
100
9090
8070
304020
10
0
(a)
3D distanceFluctuation sphere plot
!10
010
20
30
40
50
0 5 10 15 20
acquis
ition tim
e [m
in]
movement [mm]
10
sig
n.m
otio
n fo
un
d o
n a
rtifica
l he
ad
su
rfac
e (r=
10
0m
m)
3 s
ign
.mo
tion
fou
nd
in m
ea
n s
triatu
m a
rea
s
"be
st" p
oin
t on
he
ad
su
rface
"wo
rst" p
oin
t on
he
ad
su
rface
L s
triatu
m [p
1=
56
:60
:36
]
R s
triatu
m [p
2=
78
:60
:36
]
po
int o
f mo
tion
> 4
mm
fram
e b
ou
nd
arie
s
acce
ssib
le ra
ng
e o
n h
ea
d s
urfa
ce
"best" p
oin
t on
head
su
rface (1
0%!
90%
) = 0
.8!
7.5
mm
min
imum
movem
ent [m
m]
Frequency
02
46
8
0 2000 4000
"wo
rst" p
oin
t on
head
su
rface (1
0%!
90%
) = 0
.8!
17.7
mm
maxim
um
movem
ent [m
m]
Frequency
05
10
15
20
0 2000 4000 6000
sphere
angle
!! [d
eg]
sphere angle "" [deg]
045
90
135
180
225
270
315
360
0 45 90 135 180
Ne
ck
Os te
mp
ora
le (L
)
Os p
arie
tale
Ne
ck
Os n
asa
le
Os p
arie
tale
Ne
ck
Os te
mp
ora
le (R
)
Os p
arie
tale
Ne
ck
Os o
ccip
itale
Os p
arie
tale
dis
tan
ce
fluc
tua
tion
ma
p (s
d.) !
ma
x. =
+/!
7.3
mm
0 1 2 3 4 5 6 7
sphere
angle
!! [d
eg]
sphere angle "" [deg]
045
90
135
180
225
270
315
360
0 45 90 135 180
Ne
ck
Os te
mp
ora
le (L
)
Os p
arie
tale
Ne
ck
Os n
asa
le
Os p
arie
tale
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ck
Os te
mp
ora
le (R
)
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arie
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ck
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ccip
itale
Os p
arie
tale
me
an
dis
tan
ce
to s
ou
rce
po
int m
ap
! m
ax
. = 1
0.1
mm
0 2 4 6 8 10
Patie
nt h
ead m
ovem
ent a
naly
sis
with
sig
nific
ant m
otio
n (>
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m) s
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Page 2
/3./h
ackbarth
_070911.tfm
Tue S
ep 1
1 1
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(b)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
List-mode: Measuring principle of PET
21
CoincidenceProcessing Unit
Image ReconstructionAnnihilation
Coincidence Data(Sinogram/List-mode)
e+
e−
γ
γ
ν
• Registration of coincidences (events) between two detectorsi.e. Line-of-Response (LOR)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
PET acquisition - why list-mode?
• highest time and data resolution possible(raw data vs. compression of LORs with sinograms)
• allows to retrospectively change the framing scheme
• modification of coincidence data prior to image reconstruction(e.g. apply motion correction, list-mode based reconstructions, etc.)
22
“framing and histograming“(sinogram generation)
time coincidence events (“list mode stream”)
… …
1 2 3 4 . . . . . n-1. n n+1 . . N
image reconstruction
… …
time frames
data storage(hard disk)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
List-mode problems with ECAT scanners (HR+)
• Direct access to list-mode data often limited or not supported at all(! 0.5 MB/s with an ECAT EXACT HR+)
! no clinical usability due to long transfer timese.g. for a typical amount of 4-6 GB ! 3 hours
0.5 MB/s
acquisition system (ACS)
image reconstruction
10 MB/s
[1] Langner, J. et. al; Z. Med. Phys. 2006; 16(1):75-82.
23
PETgantry
Method A:
70 MB/s
SCSI-RAID(dual channel)
LinuxSystem
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
List-mode problems with ECAT scanners (HR+)
• Direct access to list-mode data often limited or not supported at all(! 0.5 MB/s with an ECAT EXACT HR+)
! no clinical usability due to long transfer timese.g. for a typical amount of 4-6 GB ! 3 hours
0.5 MB/s
acquisition system (ACS)
image reconstruction
10 MB/s
1 GBit/s
• optimised data access by providing a different data access path(! 70 MB/s using dual-channel SCSI-RAID system)
! allows transfer < 1 min [1] Langner, J. et. al; Z. Med. Phys. 2006; 16(1):75-82.
23
PETgantry
Method A:
HD
fiber-optic
ACS2
M1M2
M3 opto-electronicadapter
Linux
HDDAQ
externaldata bus
DAQcards
ACS2data bus
optocoupler
powersource
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
List-mode problems with ECAT scanners (HR+)
24
Method B:
[1] Langner, J. et. al; Z. Med. Phys. 2006; 16(1):75-82.
adapter card
HD
fiber-optic
ACS2
M1M2
M3 opto-electronicadapter
Linux
HDDAQ
externaldata bus
DAQcards
ACS2data bus
optocoupler
powersource
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
List-mode problems with ECAT scanners (HR+)
24
Method B:
[1] Langner, J. et. al; Z. Med. Phys. 2006; 16(1):75-82.
• optocoupler-based adapter card to read out the list-mode data directly from an external data bus of ACS
! receive coincidences in real-time during acquisition
! apply motion correction or image reconstruction in real-time
adapter card
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Event-based motion correction
• Method:
1.spatial transformation of all registered events
2.sorting events into sinograms
3.apply standard reconstruction(e.g. OSEM)
• complications:
1. detector normalisation
2. LOR discretisation
3. Out-of-FOV correctionschematic view
25
[1] Bühler, P., et. al; IEEE T MED IMAGING 23(9) 2004
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Event-based motion correction
• Method:
1.spatial transformation of all registered events
2.sorting events into sinograms
3.apply standard reconstruction(e.g. OSEM)
• complications:
1. detector normalisation
2. LOR discretisation
3. Out-of-FOV correctionschematic view
25
[1] Bühler, P., et. al; IEEE T MED IMAGING 23(9) 2004
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Event-based motion correction
• Method:
1.spatial transformation of all registered events
2.sorting events into sinograms
3.apply standard reconstruction(e.g. OSEM)
• complications:
1. detector normalisation
2. LOR discretisation
3. Out-of-FOV correctionschematic view
25
[1] Bühler, P., et. al; IEEE T MED IMAGING 23(9) 2004
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Event-based motion correction
D1
D2
• Method:
1.spatial transformation of all registered events
2.sorting events into sinograms
3.apply standard reconstruction(e.g. OSEM)
• complications:
1. detector normalisation
2. LOR discretisation
3. Out-of-FOV correctionschematic view
25
[1] Bühler, P., et. al; IEEE T MED IMAGING 23(9) 2004
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Event-based motion correction
D1
D2
• Method:
1.spatial transformation of all registered events
2.sorting events into sinograms
3.apply standard reconstruction(e.g. OSEM)
• complications:
1. detector normalisation
2. LOR discretisation
3. Out-of-FOV correctionschematic view
25
[1] Bühler, P., et. al; IEEE T MED IMAGING 23(9) 2004
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Event-based motion correction
D1
D2
D1´
D2´
• Method:
1.spatial transformation of all registered events
2.sorting events into sinograms
3.apply standard reconstruction(e.g. OSEM)
• complications:
1. detector normalisation
2. LOR discretisation
3. Out-of-FOV correctionschematic view
25
[1] Bühler, P., et. al; IEEE T MED IMAGING 23(9) 2004
• „Loss“ of events due to the transformation of LORs outside the field-of-view (FOV)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Out-of-FOV correction
26
schematic view
• „Loss“ of events due to the transformation of LORs outside the field-of-view (FOV)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Out-of-FOV correction
26
schematic view 30s
• „Loss“ of events due to the transformation of LORs outside the field-of-view (FOV)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Out-of-FOV correction
26
schematic view 30s
• „Loss“ of events due to the transformation of LORs outside the field-of-view (FOV)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Out-of-FOV correction
26
schematic view 30s30s
• „Loss“ of events due to the transformation of LORs outside the field-of-view (FOV)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Out-of-FOV correction
26
schematic view 30s30s
f =Acqtime
Acqtime−Out-of-FOV-time
Ncorrected = Nmeasured · f
[1] Bühler, P., et. al; IEEE T MED IMAGING 23(9) 2004
• Initial approach [1]:
• „Loss“ of events due to the transformation of LORs outside the field-of-view (FOV)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Out-of-FOV correction
26
schematic view 30s
! This approach does not always solve the problem:
Sagittal
0,0
5986
Bq/c
c
30s
f =Acqtime
Acqtime−Out-of-FOV-time
Ncorrected = Nmeasured · f
[1] Bühler, P., et. al; IEEE T MED IMAGING 23(9) 2004
• Initial approach [1]:
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Optimisation Out-of-FOV correction
27
acquisition time [min]
posi
tion [
mm
]
discrete patient motion (example)
Method:
Goal: minimisation of Out-of-FOV factors
• Original approach:
transformation of all events to acquisition start (tref =0)
• Optimised approach:
1. Analysis of motion data
2. Identify optimal reference time(tref = topt)
• condition: position in which the patient has been most of the time
3. Transformation of all events totime tref
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Optimisation Out-of-FOV correction
27
acquisition time [min]
posi
tion [
mm
]
discrete patient motion (example)
tref = 0
Method:
Goal: minimisation of Out-of-FOV factors
• Original approach:
transformation of all events to acquisition start (tref =0)
• Optimised approach:
1. Analysis of motion data
2. Identify optimal reference time(tref = topt)
• condition: position in which the patient has been most of the time
3. Transformation of all events totime tref
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Optimisation Out-of-FOV correction
27
acquisition time [min]
posi
tion [
mm
]
discrete patient motion (example)
topttref = 0
Method:
Goal: minimisation of Out-of-FOV factors
• Original approach:
transformation of all events to acquisition start (tref =0)
• Optimised approach:
1. Analysis of motion data
2. Identify optimal reference time(tref = topt)
• condition: position in which the patient has been most of the time
3. Transformation of all events totime tref
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Optimisation Out-of-FOV correction
27
tref =
acquisition time [min]
posi
tion [
mm
]
discrete patient motion (example)
topt
Method:
Goal: minimisation of Out-of-FOV factors
• Original approach:
transformation of all events to acquisition start (tref =0)
• Optimised approach:
1. Analysis of motion data
2. Identify optimal reference time(tref = topt)
• condition: position in which the patient has been most of the time
3. Transformation of all events totime tref
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Results of optimized Out-of-FOV correction
28
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15
10
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15
10
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15
10
50
100
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15
10
50
100
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15
10
50
100
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!
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6
15
10
50
100
500
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non!optimised OFOV correction
optimised OFOV correction
Distribution of Out-of-FOV factorsO
FOV fac
tor
Distribution of Out-of-FOV factors (boxplot)
data set
non-optimisedoptimised
• Noticable reduction of Out-of-FOV factors
• Noticable reduction of image artefacts
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Results of optimized Out-of-FOV correction
28
(a)
(b)
059
81Bq
/ml
Transaxial Coronal Sagittal
Qualitative Comparisonqualitative comparison
withoutOptimisation
withOptimisation
• Noticable reduction of Out-of-FOV factors
• Noticable reduction of image artefacts
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Results of MC - point source evaluations
29
At rest(reference image)
WithoutMotion Correction
WithMotion Correction
Qualitative Comparison
[MBq
/ml]
0.00
2.37t: 5-10 min t: 5-10 mint: 0-5 min
5 mm
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Results of MC - example patient data I
withoutmotion correction
male, 64 yearsdifferential diagnosesM. Parkinson
PET acquisition:F-18 DOPA171 MBq i.v.10 min transmission55 min emission(27 frames)
detected motion:1,2 - 19,4 mmmean: 11,3 mm
conce
ntr
atio
n [
Bq/c
c]0.0
4344.6
7
• better delineation of the striatum
• reduction of image artefacts
Transaxial Transaxial
30
withmotion correction
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Results of MC - example patient data I
31
Quantitative evaluation via a tracer kinetics analysis:
• standard procedure at our PET centre for M. Parkinson evaluation:
1.positioning of 8 region-of-interest (ROI) in the striatum+ 1 ROI in the occipital lobe as a reference tissue
2.comparison of time-activity-curves (TAC); calculation of the tracer kinetics parameter R0k3 on the base of an irreversible reference tissue two compartment model (Patlak plot)
ncrpra
prmprpref
nclpla
plpplm
|�a|>| �b|>|�c|>| �d|>|�e|�
��� �=| �a �|>| �e �|>| �d �|>| �c �|>| �b �|
���
�|�a|>| �b|>|�c|>| �d|>|�e|�
��� �=| �a �|>| �e �|>| �d �|>| �c �|>| �b �|
���
�
ncr nucleus caudatus right
nucleus caudatus leftnclpra putamen right anterior
prm putamen right mediusprp putamen right posterior
pla putamen left anterior
plm putamen left medius
plp putamen left posterior
ref reference ROI
pr
pl
quantitative evaluation
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Results of MC - example patient data I
32
• relevant change of R0k3
! e.g. ! 230 % in ncl
without MC
ROI volume [cc]
R0k 3
mea
n [
1/m
in]
with MC
0.52 0.52 1.6 1.6 0.52 0.52 0.52 0.52 0.52 0.52
original_roi_patlak.txt
Volume (0.524445)
R0
k3
0.0
00
0.0
05
0.0
10
0.0
15
roi.n
cr
roi.n
cl
roi.p
r
roi.p
l
roi.p
ra
roi.p
rm
roi.p
rp
roi.p
la
roi.p
lm
roi.p
lp
0.0156
0.0046
0.0019
0.0041 0.0042
0.0032
0.0022
0.0095
!0.0008
0.0013
0.52 0.52 1.6 1.6 0.52 0.52 0.52 0.52 0.52 0.52
corrected_roi_patlak.txt
Volume (0.524445)
R0
k3
0.0
00
0.0
05
0.0
10
0.0
15
roi.n
cr
roi.n
cl
roi.p
r
roi.p
l
roi.p
ra
roi.p
rm
roi.p
rp
roi.p
la
roi.p
lm
roi.p
lp
0.0127
0.0105
0.0095 0.0095 0.0094
0.0110
0.0088 0.0089
0.0080
0.0102
ncr
ncl
pr
pl
0.52 0.52 1.6 1.6 0.52 0.52 0.52 0.52 0.52 0.52
original_roi_patlak.txt
Volume (0.524445)
R0
k3
0.0
00
0.0
05
0.0
10
0.0
15
roi.n
cr
roi.n
cl
roi.p
r
roi.p
l
roi.p
ra
roi.p
rm
roi.p
rp
roi.p
la
roi.p
lm
roi.p
lp
0.0156
0.0046
0.0019
0.0041 0.0042
0.0032
0.0022
0.0095
!0.0008
0.0013
0.52 0.52 1.6 1.6 0.52 0.52 0.52 0.52 0.52 0.52
corrected_roi_patlak.txt
Volume (0.524445)
R0
k3
0.0
00
0.0
05
0.0
10
0.0
15
roi.n
cr
roi.n
cl
roi.p
r
roi.p
l
roi.p
ra
roi.p
rm
roi.p
rp
roi.p
la
roi.p
lm
roi.p
lp
0.0127
0.0105
0.0095 0.0095 0.0094
0.0110
0.0088 0.0089
0.0080
0.0102
ncr
ncl
pr
pl
ncr
pr
ref
ncl
pl|�a|>| �b|>|�c|>| �d|>|�e|�
��� �=| �a �|>| �e �|>| �d �|>| �c �|>| �b �|
���
�|�a|>|� b|>|�c|>|� d|>|�e|
�����=|� a� |>|� e� |>|� d� |>|� c� |>|� b� |
����
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Results of MC - example patient data II
time-activity-curve
Bq/c
c0.0
10290.0
0 5 10 15 20 25 30 35 40 45 50
10.000
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Zeit [min]
Konzentr
ati
on [
Bq/cc]
with MC
without MC Transaxial
male, 75 yearsF-18 DOPA (M. Parkinson)248 MBq i.v.55 min emission(27 frames)
33
time [min]
conce
ntr
atio
n [
Bq/c
c]
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Clinical Integration - Graphical User Interfaces
(a) (b)
34
!10 0 10 20 30 40 50
05
10
15
20
acquisition time [min]
movem
ent [m
m]
10 sign.motion found on artifical head surface (r=100mm)3 sign.motion found in mean striatum areas
"best" point on head surface
"worst" point on head surface
L striatum [p1=56:60:36]
R striatum [p2=78:60:36]
point of motion > 4 mm
frame boundaries
accessible range on head surface
"best" point on head surface (10%!90%) = 0.8!7.5 mm
minimum movement [mm]
Fre
quency
0 2 4 6 8
02000
4000
"worst" point on head surface (10%!90%) = 0.8!17.7 mm
maximum movement [mm]
Fre
quency
0 5 10 15 20
02000
4000
6000
sphere angle !! [deg]
sphere
angle
"" [deg]
0 45 90 135 180 225 270 315 360
045
90
135
180
Neck
Os temporale (L)
Os parietale
Neck
Os nasale
Os parietale
Neck
Os temporale (R)
Os parietale
Neck
Os occipitale
Os parietale
distance fluctuation map (sd.) ! max. = +/!7.3 mm
01
23
45
67
sphere angle !! [deg]
sphere
angle
"" [deg]
0 45 90 135 180 225 270 315 360
045
90
135
180
Neck
Os temporale (L)
Os parietale
Neck
Os nasale
Os parietale
Neck
Os temporale (R)
Os parietale
Neck
Os occipitale
Os parietale
mean distance to source point map ! max. = 10.1 mm
02
46
810
Patient head movement analysis with significant motion (> 4 mm) selected:
Page 2/3./hackbarth_070911.tfm
Tue Sep 11 13:58:11 2007analyze_trk.R $Revision: 195 $ ! (c) 2005!2007 fzd.de
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Clinical Integration - Motion report pages
35
Analysed subject:Acquisition time:Total # motions:
Cross!Calibration:
./hackbarth_070911.trk55.00 min42674 (a 77 ms)cc_070901.tfm
X Y ZReference target motion:(should be ~0.0)
0.059 0.023 0.026 [mm]0.001 0.004 0.004 [deg]
X Y ZPatient target motion: 2.554 11.007 12.657 [mm]
5.162 1.373 1.783 [deg]
Head movement analysis on head surface (r=100mm):
'best' point on head surface:
'worst' point on head surface:
distance fluctuation:
mean distance:
10 sign. motions > 4 mm0.8!7.5 mm
0.8!17.7 mm
max. +/! 7.3 mm
max. 10.1 mm
on 'mean striatum' areas:L striatum [56:60:36]:
R striatum [78:60:36]:
3 sign. motions > 4 mm0.0!14.5 mm
0.0!14.4 mm
Estimated Score:(1: no motion, 2: low motion, 3: moderate motion,
4: significant motion, 5: high motion)5
Page 1/3
./hackbarth_070911.trk
Tue Sep 11 13:58:11 2007
analyze_trk.R $Revision: 195 $ ! (c) 2005!2007 fzd.de
Motion!Tracking SummaryTue Sep 11 13:58:11 2007
Analysed subject:Acquisition time:Total # motions:
Cross!Calibration:
./hackbarth_070911.trk55.00 min42674 (a 77 ms)cc_070901.tfm
X Y ZReference target motion:(should be ~0.0)
0.059 0.023 0.026 [mm]0.001 0.004 0.004 [deg]
X Y ZPatient target motion: 2.554 11.007 12.657 [mm]
5.162 1.373 1.783 [deg]
Head movement analysis on head surface (r=100mm):
'best' point on head surface:
'worst' point on head surface:
distance fluctuation:
mean distance:
10 sign. motions > 4 mm0.8!7.5 mm
0.8!17.7 mm
max. +/! 7.3 mm
max. 10.1 mm
on 'mean striatum' areas:L striatum [56:60:36]:
R striatum [78:60:36]:
3 sign. motions > 4 mm0.0!14.5 mm
0.0!14.4 mm
Estimated Score:(1: no motion, 2: low motion, 3: moderate motion,
4: significant motion, 5: high motion)5
Page 1/3
./hackbarth_070911.trk
Tue Sep 11 13:58:11 2007
analyze_trk.R $Revision: 195 $ ! (c) 2005!2007 fzd.de
Motion!Tracking SummaryTue Sep 11 13:58:11 2007
Analysed subject:Acquisition time:Total # motions:
Cross!Calibration:
./hackbarth_070911.trk55.00 min42674 (a 77 ms)cc_070901.tfm
X Y ZReference target motion:(should be ~0.0)
0.059 0.023 0.026 [mm]0.001 0.004 0.004 [deg]
X Y ZPatient target motion: 2.554 11.007 12.657 [mm]
5.162 1.373 1.783 [deg]
Head movement analysis on head surface (r=100mm):
'best' point on head surface:
'worst' point on head surface:
distance fluctuation:
mean distance:
10 sign. motions > 4 mm0.8!7.5 mm
0.8!17.7 mm
max. +/! 7.3 mm
max. 10.1 mm
on 'mean striatum' areas:L striatum [56:60:36]:
R striatum [78:60:36]:
3 sign. motions > 4 mm0.0!14.5 mm
0.0!14.4 mm
Estimated Score:(1: no motion, 2: low motion, 3: moderate motion,
4: significant motion, 5: high motion)5
Page 1/3
./hackbarth_070911.trk
Tue Sep 11 13:58:11 2007
analyze_trk.R $Revision: 195 $ ! (c) 2005!2007 fzd.de
Motion!Tracking SummaryTue Sep 11 13:58:11 2007
(a)
(b)
(c)
(d)
doe_070911.trk
40
50
60
Neck
70
80
0350
340
10
3020
40 50 60 80709090
100
150
140
130
110120
160
170
180
190
200
300
310
320
330
100
Os temporale (L)
110
120
Os nasale
130
Min point
Max point
140
150
160
170180
Os parietale
Os temporale (R)Os occipitale
290
280
270
260250
240 220230
210
0
10
20
30
Neck
50
60
70
80
10
20
30
0
350
40
5060
100
110
120
130
150
140
160
170
190
180
200210
220230 240 250 260 270
280290
300
310
320
340
330Os temporale (R)
Os occipitale
Os parietale
180
170
160
150
Os temporale (L)
140
Max point
Min point
130
120
Os nasale
110
100
9090
8070
304020
10
0
!10 0 10 20 30 40 50
05
10
15
20
acquisition time [min]
mo
ve
me
nt
[mm
]
10 sign.motion found on artifical head surface (r=100mm)3 sign.motion found in mean striatum areas
"best" point on head surface
"worst" point on head surface
L striatum [p1=56:60:36]
R striatum [p2=78:60:36]
point of motion > 4 mm
frame boundaries
accessible range on head surface
"best" point on head surface (10%!90%) = 0.8!7.5 mm
minimum movement [mm]
Fre
qu
en
cy
0 2 4 6 8
02
00
04
00
0
"worst" point on head surface (10%!90%) = 0.8!17.7 mm
maximum movement [mm]
Fre
qu
en
cy
0 5 10 15 20
02
00
04
00
06
00
0
sphere angle !! [deg]
sp
he
re a
ng
le ""
[d
eg
]
0 45 90 135 180 225 270 315 3600
45
90
13
51
80
Neck
Os temporale (L)
Os parietale
Neck
Os nasale
Os parietale
Neck
Os temporale (R)
Os parietale
Neck
Os occipitale
Os parietale
distance fluctuation map (sd.) ! max. = +/!7.3 mm
01
23
45
67
sphere angle !! [deg]
sp
he
re a
ng
le ""
[d
eg
]
0 45 90 135 180 225 270 315 360
04
59
01
35
18
0
Neck
Os temporale (L)
Os parietale
Neck
Os nasale
Os parietale
Neck
Os temporale (R)
Os parietale
Neck
Os occipitale
Os parietale
mean distance to source point map ! max. = 10.1 mm
02
46
81
0
Patient head movement analysis with significant motion (> 4 mm) selected:
Page 2/3./hackbarth_070911.tfm
Tue Sep 11 13:58:11 2007analyze_trk.R $Revision: 195 $ ! (c) 2005!2007 fzd.de
(a)
3D distanceFluctuation sphere plot
!10
010
20
30
40
50
0 5 10 15 20
acquis
ition tim
e [m
in]
movement [mm]
10 s
ign
.mo
tion
fou
nd
on
artific
al h
ead
su
rface (r=
100m
m)
3 s
ign
.mo
tion
fou
nd
in m
ean
stria
tum
are
as
"best" p
oin
t on h
ead s
urfa
ce
"wors
t" poin
t on h
ead s
urfa
ce
L s
triatu
m [p
1=
56:6
0:3
6]
R s
triatu
m [p
2=
78:6
0:3
6]
poin
t of m
otio
n >
4 m
m
fram
e b
oundarie
s
accessib
le ra
nge o
n h
ead s
urfa
ce
"best" p
oin
t on
head
su
rface (1
0%!
90%
) = 0
.8!
7.5
mm
min
imum
movem
ent [m
m]
Frequency
02
46
80 2000 4000
"wo
rst" p
oin
t on
head
su
rface (1
0%!
90%
) = 0
.8!
17.7
mm
maxim
um
movem
ent [m
m]
Frequency
05
10
15
20
0 2000 4000 6000
sphere
angle
!! [d
eg]
sphere angle "" [deg]
045
90
135
180
225
270
315
360
0 45 90 135 180
Neck
Os te
mpora
le (L
)
Os p
arie
tale
Neck
Os n
asale
Os p
arie
tale
Neck
Os te
mpora
le (R
)
Os p
arie
tale
Neck
Os o
ccip
itale
Os p
arie
tale
dis
tan
ce flu
ctu
atio
n m
ap
(sd
.) ! m
ax. =
+/!
7.3
mm
0 1 2 3 4 5 6 7
sphere
angle
!! [d
eg]
sphere angle "" [deg]
045
90
135
180
225
270
315
360
0 45 90 135 180
Neck
Os te
mpora
le (L
)
Os p
arie
tale
Neck
Os n
asale
Os p
arie
tale
Neck
Os te
mpora
le (R
)
Os p
arie
tale
Neck
Os o
ccip
itale
Os p
arie
tale
mean
dis
tan
ce to
so
urc
e p
oin
t map
! m
ax. =
10.1
mm
0 2 4 6 8 10
Pa
tien
t he
ad
mo
ve
me
nt a
na
lysis
with
sig
nific
an
t mo
tion
(> 4
mm
) se
lecte
d:
Page 2
/3./h
ackbarth
_070911.tfm
Tue S
ep 1
1 1
3:5
8:1
1 2
007
an
aly
ze
_trk
.R $
Re
vis
ion
: 19
5 $
! (c
) 20
05!
20
07
fzd
.de
[mm]
(b)
(c)
(d)
• patient motion has a potentially high influence on the image quality and on the accuracy of a tracer kinetics analysis
• a quantitative motion compensation is possible, can be integrated into clinical routine and helps minimising or even eliminating motion related effects
• the quantification of patient motion via an external motion tracking device is independent from applying a motion correction and provides additional information for the evaluation of questionable image artifacts
• a motion correction can be an important factor for the possibility to perform certain studies (e.g. in case of long scan times)
• the amount of „lost scans“ due to patient motion can be reduced in clinical routine
• parts of the methods have already been transfered to another centre(Forschungszentrum Jülich, Germany)
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Conclusion / Summary
36
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Patient study underway...
0-3 mm34%
3-5 mm31%
5-7 mm18%
> 7 mm18%
• 912 clinically acquired brain scans incl. motion correction performed until today
– 666 F18-DOPA (M. Parkinson)
– 143 F18-FDG (M. Alzheimer)
– 54 F18-OMFD (oncology)
– 49 others
• ToDo:
1)Evaluation of the image quality improvement
2)Selection of suitable patient data for detailed analysis
3)Evaluation of the changes in tracer kinetics due to the motion compensationmaximum motion
detected
37
• Jörg van den Hoff
• Paul Bühler
• Frank Hofheinz
• Jens Langner
• Uwe Just
• Hagen Mölle
• Christian Pötzsch
• Edmund Will
• Sören Dittrich
Institue of Radiopharmacy - PET centre ! Dr. Jens Langner ! www.fzd.de ! November 10, 2009 /38
Who made it possible?
Danke für Ihre
Aufmerksamkeit38
• Bettina Beuthien-Baumann
• Liane Oehme
... and the city of Dresden